When I heard that the actor John Tur­turro had directed a documentary, “Pas­sione,” about the music of Naples, Italy, I braced myself for a straightforward history lesson. Since I know very little about Neapolitan music, this was not an altogether unpleasant expectation, but the dutifulness of the enterprise – its “instructional” value – was a potential turnoff.

I needn’t have worried. “Passione” is, in the best sense, educational, but it’s also anything but straightforward. What Turturro, who appears in the film as a combination tour guide and impresario, has come up with is closer to a fantasia than a traditional documentary. It’s as if that warm Neapolitan sun got to him. He loves this city and he’s deliriously happy offering up its soundscape to us.

The closest approximation to “Passione” is probably the Wim Wenders-Ry Cooder documentary “Buena Vista Social Club,” which brought to rousing, poignant life the old Havana music scene. In both films, we get the distinct impression that anybody randomly plucked off the streets could instantly offer up an aria that would make the heavens weep. Music is the lifeblood of these cultures, a way of making sense of life, of enduring it and exalting it.

But “Buena Vista” is far less hallucinatory in its effects than “Passione,” where Turturro mixes standard concert renditions with dream plays and acted-out mini-melodramas staged in the streets. With his musicians and vocalists, he blends the worlds of opera, jazz, pop, and fado, reinforcing the idea that Neapolitan culture has always been a glorious mishmash, and never more so than now, when ethnic mixing is rampant. (One Neapolitan artist explains that he feels like “everybody and nobody at the same time.”)

Turturro opens the film by telling us: “There are places where you go to and once is enough – and then there is Napoli.” A second-generation Italian-American – his mother came from Sicily, his father from Bari – he speaks Italian to the various artists he introduces us to and clearly they regard him as one of their own. He dives right into each musical sequence as if it was the centerpiece attraction. Turturro is an equal-opportunity enthusiast, which is easy to be when the attractions are as revivifying as they are here. (During some of the numbers, he even lets the microphone dip into the frame, as if to remind us that his filmmaking is part of the theatrical experience, too.)

The great Portuguese fado artist Mísia, who specializes in Neapolitan songs, performs two achingly soulful love ballads. There is also the great Tunisian transplant M’Barka Ben Taleb, with a leonine presence and pipes to match. In one of the film’s giddiest jam sessions, she, singing in Arabic, joins two other artists on a small stage – the other two are Peppe Barra and Benny Fazio (who acted in “The Sopranos”) – as they sing “Pistol Packin’ Mama.”

This song was brought to Naples during World War II by American GIs, and in their wake a horde of Italo-African-American babies were left behind with their Italian mothers. One such person is vocalist/saxophonist James Senese, who never met his father and, between sinuous sax wails, tells us about being taunted as a “half-breed.”

This is one of the few times in the film when Turturro lets slip the fact that Naples is not all paradise all the time. I suppose he errs in not bringing up the poverty, the corruption, the crime (for that, you’d have to see Matteo Garrone’s dramatic film “Gomorrah”). But we know it’s there without him rubbing our noses in it. Turturro uses our knowledge of Naples’s woes as a given. His film is about how music transcends all that, transmutes it into art.

A bigger fault is that he skimps opera. The great Caruso gets short shrift. But Turturro, in an homage to the past, artfully mixes in old footage of Neapolitan stars like Angela Luce, or Sergio Bruni singing “O Sole Mio,” which is given a rousing update by Massimo Ranieri and Taleb.

He also interviews a garrulous local chef, who, with very little prompting, sings a few bars from a song his mother sang to him as a boy. In that instant, this 67-year-old man is once again that boy.